Method for purifying flouroarylboron derivative and bis(fluoroaryl)boron derivative

ABSTRACT

After a fluoroaryl borane derivative is precipitated from a solution containing the fluoroaryl borane derivative, a bis (fluoroaryl) borane derivative, and a hydrocarbon solvent and is subjected to first filtration so that the fluoroaryl borane derivative is isolated, a filtrate that has been obtained by the first filtration is cooled and the bis (fluoroaryl) borane derivative is separated and is subjected to second filtration so that the bis (fluoroaryl) borane derivative is isolated. In a case where the solution contains fluorobenzene, the solution is concentrated, so that the fluorobenzene is removed. Thus, it is possible to provide the high-purity fluoroaryl borane derivative and bis (fluoroaryl) borane derivative having no impurity with ease and at a low cost.

TECHNICAL FIELD

[0001] The present invention relates to a method for producing afluoroaryl borane derivative and a bis (fluoroaryl) borane derivativesuch as a pentafluorophenyl boronic acid and a bis (pentafluorophenyl)borinic acid, which are useful as a polymerization catalyst, apolymerization co-catalyst, a catalyst for photopolymerization ofsilicone, an intermediate thereof, and an intermediate of a medicine oran agricultural chemical, for example.

BACKGROUND ART

[0002] Fluoroaryl borane derivatives and bis (fluoroaryl) boranederivatives such as pentafluorophenyl boronic acid and bis(pentafluorophenyl) borinic acid, are compounds useful as polymerizationcatalysts, polymerization co-catalysts, catalysts forphotopolymerization of silicone, intermediates thereof, andintermediates of medicines or agricultural chemicals, for example.

[0003] For instance, as a manufacturing method of pentafluorophenylboronic acid, J. Chem. Soc (1965) 3933-3939 discloses a method in whichdichloropentafluorophenyl borane is added to acetone/water solution at atemperature of −78° C., then the acetone solution is concentrated, sothat the pentafluorophenyl boronic acid is sublimated for purification,so as to be isolated. Further, as a manufacturing method of bis(pentafluorophenyl) borinic acid, it discloses a method in which asolution of bis (pentafluorophenyl) chloro borane in acetone is added toacetone/water solution at a temperature of −20° C., then the acetonesolution is concentrated, so that the bis (pentafluorophenyl) borinicacid is sublimated for purification, so as to be isolated. Furthermore,the dichloropentafluorophenyl borane which is a precursor ofpentafluorophenyl boronic acid, and the bis (pentafluorophenyl) chloroborane, which is a precursor of bis (pentafluorophenyl) borinic acid aresynthesized by reacting pentafluorophenyl trimethyl tin or bis(pentafluorophenyl) dimethyl tin with boron trichloride. Uponsynthesizing the dichloropentafluorophenyl borane, trimethyl tinchloride is produced as a by-product, and upon synthesizing the bis(pentafluorophenyl) chloro borane, dimethyl tin dichloride is producedas a by-product. However, it is difficult to purifydichloropentafluorophenyl borane and bis (pentafluorophenyl) chloroborane by distillation for the following reason: when these reactionmixtures are distilled so as to purify dichloropentafluorophenyl boraneand bis (pentafluorophenyl) chloro borane as objects, trimethyl tinchloride reacts with an excess of boron trichloride so as to producedimethyl tin dichloride which is identical to the by-product producedupon synthesizing bis (pentafluorophenyl) chloro borane, so that thedimethyl tin dichrolide is sublimed. Thus, it is difficult to purifydichloropentafluorophenyl borane and bis (pentafluorophenyl) chloroborane with high yield.

[0004] Moreover, J. Molecular Catalysis A: Chemical 144 (1999) 137-150and WO 0037376 (2000) disclose that bis (pentafluorophenyl) borinic acidis prepared by heating a tris (pentafluorophenyl) borane hydrate.

[0005] However, the method disclosed in the above-mentioned J. MolecularCatalysis A: Chemical 144 (1999) 137-150 discloses only how tomanufacture bis (pentafluorophenyl) borinic acid, and fails to recitehow to isolate bis (pentafluorophenyl) borinic acid from a reactionmixture.

[0006] J. Molecular Catalysis A: Chemical 144 (1999) 137-150 recitesonly that it was confirmed by ¹⁹F-NMR that bis (pentafluorophenyl)borinic acid was prepared by adding water to a toluene-d8 solution oftris (pentafluorophenyl) borane so as to prepare a tris(pentafluorophenyl) borane hydrate, then heating the solution of thetris (pentafluorophenyl) borane hydrate.

[0007] Moreover, WO 0037476 (2000) discloses preparation of bis(pentafluorophenyl) borinic acid by heating a tris (pentafluorophenyl)borane hydrate, and an isolation method of bis (pentafluorophenyl)borinic acid. Specifically, a toluene solution of tris(pentafluorophenyl) borane is heated up to 100° C. Then, to thesolution, a toluene solution containing 2.5 equivalent amount of wateris dropped so that reaction carried out at 100° C. After finishing thereaction, the reaction mixture is dried in vacuo so as to isolate bis(pentafluorophenyl) borinic acid. However, it is recited that the bis(pentafluorophenyl) borinic acid obtained by this method containsboroxine by 5% as impurities. In short, this method has such a problemthat the isolated bis (pentafluorophenyl) borinic acid has a low purity.

[0008] Moreover, that patent also discloses a method in which alminiumsulfate 18 hydrate is used instead of water. Specifically, aluminiumsulfate 18 hydrate is added to a toluene solution of tris(pentafluorophenyl) borane. After the solution is refluxed, insolublealminium sulfate is separated from the reaction mixture. A solvent of afiltrate is removed in vacuo. Toluene is added to the thus obtainedresidue. After stirring, the insoluble matter passes through a G4sintered-glass so as to be separated. The solvent of the filtrate isagain removed in vacuo. Heptane is added to the residue. The solution isstirred and filtered so that a cake is obtained. Finally, the thusobtained cake is washed with heptane, and dried in vacuo so as toisolate bis (pentafluorophenyl) borinic acid. However, this method hassuch a problem that it is necessary to remove the byproduct alminiumsulfate and its process is so complicated.

[0009] As described above, the prior methods have many problems to beimproved. Although conditions of reduced pressure etc. are unexplained,boroxine is generated as impurity. Thus, in the case where the bis(fluoroaryl) borane derivative containing impurities is used aspolymerization catalyst for example, there occur such problems thatpolymerization activity declines, etc.

[0010] Therefore, for industrial application of a fluoroaryl boranederivative and a bis (fluoroaryl) borane derivative, such aspentafluorophenyl boronic acid and bis (pentafluorophenyl) borinic acid,as catalysts or the like, there is a desire for a method by which thehighly-purified fluoroaryl borane derivative and bis (fluoroaryl) boranederivative are easily isolated from a reaction mixture, and highlypurified. Thus, the present invention, which is contrived in view of theforegoing problems, has an object of providing a method by which afluoroaryl borane derivative and a bis (fluoroaryl) borane derivativecan be produced, isolated, and highly purified with ease.

DISCLOSURE OF INVENTION

[0011] The present invention, in order to attain the above-mentionedobject, carried out intensive studies on a method for purifying afluoroaryl borane derivative and a bis (fluoroaryl) borane derivative,especially on a condition for filtrating, a condition for purifying, andthe like. As a result, they found a method for purifying by which it ispossible to readily separate the fluoroaryl borane derivative and thebis (fluoroaryl) borane derivative respectively as desired. Furthermore,they found a method for obtaining such an object that the content of aspecific compound contained in the fluoroaryl borane derivative or thebis (fluoroaryl) borane derivative as impurities is not more than aspecific amount, thus completing the present invention.

[0012] Compared with the prior arts, the fluoroaryl borane derivativeand the bis (fluoroaryl) borane derivative obtained by the foregoingmethod for purifying are highly purified, so that it is possible topreferably use them as polymerization catalysts having highpolymerization activity.

[0013] That is, in order to solve the foregoing problems, a method ofthe present invention for purifying a fluoroaryl borane derivative and abis (fluoroaryl) borane derivative includes the steps of: precipitatingthe fluoroaryl borane derivative from a solution containing a fluoroarylborane derivative, a bis (fluoroaryl) borane derivative, and ahydrocarbon solvent; performing first filtration; cooling a filtratethat has been obtained by the first filtration; precipitating the bis(fluoroaryl) borane derivative from the filtrate; and performing secondfiltration, and the fluoroaryl borane derivative is represented byGeneral Formula (1):

[0014] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents a hydrogenatom or a hydrocarbon group, and M represents an atom belonging to Group5B or Group 6B, and n represents 0 or 1), and the bis (fluoroaryl)borane derivative is represented by General Formula (2):

[0015] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents a hydrogenatom or a hydrocarbon group, and M represents an atom belonging to Group5B or Group 6B, and n represents 0 or 1).

[0016] According to the arrangement, it is possible to purify thefluoroaryl borane derivative and the bis (fluoroaryl) borane derivativefrom a solution containing the fluoroaryl borane derivative, the bis(fluoroaryl) borane derivative, and the hydrocarbon solvent with easeand at a low cost.

[0017] That is, since the solubility of bis (fluoroaryl) boranederivative with respect to the hydrocarbon solvent is higher than thatof the fluoroaryl borane derivative and they are greatly different fromeach other, it is possible to selectively precipitate only thefluoroaryl borane derivative without precipitating the bis (fluoroaryl)borane derivative from the solution containing the fluoroaryl boranederivative, the bis (fluoroaryl) borane derivative, and the hydrocarbonsolvent within a range of a specific temperature.

[0018] Thus, the solution is set to be in the range of a specifictemperature, so that it is possible to selectively precipitate only thefluoroaryl borane derivative from the solution. Since the depositprecipitated from the solution can be readily isolated by filtration,the first filtration enables the fluoroaryl borane derivative to beisolated from the solution with ease.

[0019] That is, since the solubility of bis (fluoroaryl) boranederivative with respect to the hydrocarbon solvent is higher than thatof the fluoroaryl borane derivative, almost all or all the depositprecipitated at a specific temperature range is the fluoroaryl boranederivative, almost all or all the bis (fluoroaryl) borane derivativedissolves in the filtrate that has been obtained by the firstfiltration. Since the solubility of bis (fluoroaryl) borane derivativedeclines corresponding to a decline in a temperature, it is possible toprecipitate the bis (fluoroaryl) borane derivative that has dissolved inthe filtrate by cooling the filtrate.

[0020] In this manner, after the fluoroaryl borane derivative isisolated from the solution by the first filtration, a crystal of the bis(fluoroaryl) borane derivative is precipitated from the filtrate as adeposit, so that the bis (fluoroaryl) borane derivative can be isolatedas a solid by the second filtration.

[0021] Thus, it is possible to isolate the fluoroaryl borane derivativeand the bis (fluoroaryl) borane derivative respectively from thesolution containing the fluoroaryl borane derivative, the bis(fluoroaryl) borane derivative, and the hydrocarbon solvent. Namely, itis possible to purify the fluoroaryl borane derivative and the bis(fluoroaryl) borane derivative respectively.

[0022] Therefore, according to the method of the present invention forpurifying, it is possible to readily isolate and purify the fluoroarylborane derivative and the bis (fluoroaryl) borane derivative from thereaction solvent containing the fluoroaryl borane derivative and the bis(fluoroaryl) borane derivative without including industriallyundesirable steps such as drying up the solvent. That is, according tothe method of the present invention for purifying, it is possible topurify the fluoroaryl borane derivative and the bis (fluoroaryl) boranederivative respectively so as to enable them to be used as a catalystetc. industrially.

[0023] In order to solve the foregoing problems, a method of the presentinvention for purifying a fluoroaryl borane derivative and a bis(fluoroaryl) borane derivative includes the steps of: precipitating thefluoroaryl borane derivative from a solution containing the fluoroarylborane derivative, the bis (fluoroaryl) borane derivative,fluorobenzene, and a hydrocarbon solvent; performing first filtration sothat the fluoroaryl borane derivative is isolated; precipitating the bis(fluoroaryl) borane derivative from a filtrate that has been obtained bythe first filtration; and performing second filtration so that the bis(fluoroaryl) borane derivative is isolated as a solid, and thefluoroaryl borane derivative is represented by General Formula (1):

[0024] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), and the bis(fluoroaryl) borane derivative is represented by General Formula (2):

[0025] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ representingthe fluorine atom, and each of R⁶ and R⁷ independently represents one ofa hydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), and thefluorobenzene is represented by General Formula (3):

[0026] (where each of R⁹, R¹⁰, R¹¹, R¹², and R¹³ independentlyrepresents one of a hydrogen atom, a fluorine atom, a hydrocarbon group,and an alkoxy group, and at least one of R⁹, R¹⁰, R¹¹, R¹², and R¹³represents the fluorine atom, R⁸ represents one of a hydrogen atom and ahydrocarbon group).

[0027] According to the arrangement, it is possible to readily isolateand purify the fluoroaryl borane derivative and the bis (fluoroaryl)borane derivative respectively as solids from the solution containingthe fluoroaryl borane derivative, the bis (fluoroaryl) boranederivative, the fluorobenzene, and the hydrocarbon solvent.

[0028] That is, the fluoroaryl borane derivative obtained by the firstfiltration is isolated from the solution containing the fluoroarylborane derivative, the bis (fluoroaryl) borane derivative, thefluorobenzene, and the hydrocarbon solvent, and the filtrate is cooledso as to precipitate the bis (fluoroaryl) borane derivative, then thesecond filtration is performed, so that it is possible to isolate thebis (fluoroaryl) borane derivative as a solid.

[0029] Thus, it is possible to isolate the fluoroaryl borane derivativeand the bis (fluoroaryl) borane derivative respectively from thesolution containing the fluoroaryl borane derivative, the bis(fluoroaryl) borane derivative, the fluorobenzene, and the hydrocarbonsolvent. Namely, it is possible to purify the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative respectively fromthe solution.

[0030] Thus, according to the method of the present invention forpurifying, it is possible to readily purify the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative respectively fromthe reaction mixture containing the fluoroaryl borane derivative, thebis (fluoroaryl) borane derivative, and the fluorobenzene. That is,according to the method of the present invention for purifying, it ispossible to purify the fluoroaryl borane derivative and the bis(fluoroaryl) borane derivative so as to industrially use them ascatalysts.

[0031] In order to solve the foregoing problems, a method of the presentinvention for purifying the fluoroaryl borane derivative and the bis(fluoroaryl) borane derivative includes the steps of: concentrating asolution containing the fluoroaryl borane derivative, the bis(fluoroaryl) borane derivative, fluorobenzene, and a hydrocarbon solventso as to remove the fluorobenzene from the solution; precipitating, thefluoroaryl borane derivative; performing first filtration; cooling afiltrate that has been obtained by the first filtration; precipitatingthe bis (fluoroaryl) borane derivative; and performing secondfiltration, and the fluoroaryl borane derivative is represented byGeneral Formula (1):

[0032] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), and the bis(fluoroaryl)borane derivative is represented by General Formula (2):

[0033] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), and thefluorobenzene is represented by General Formula (3):

[0034] (where each of R⁹, R¹⁰, R¹¹, R¹², and R¹³ independentlyrepresents one of a hydrogen atom, a fluorine atom, a hydrocarbon group,and an alkoxy group, and at least one of R⁹, R¹⁰, R¹¹, R¹², and R¹³representing the fluorine atom, and R⁸ represents one of a hydrogen atomand a hydrocarbon group).

[0035] According to the arrangement, it is possible to isolate thefluoroaryl borane derivative and the bis (fluoroaryl) borane derivativeas solids from the solution containing the fluoroaryl borane derivative,the bis (fluoroaryl) borane derivative, the fluorobenzene, and thehydrocarbon solvent with ease, so as to purify them.

[0036] That is, it is possible to remove the fluorobenzene from thesolution as distillate by concentrating the solution containing thefluoroaryl borane derivative and the bis (fluoroaryl) borane derivative,the fluorobenzene, and the hydrocarbon solvent. Next, the fluoroarylborane derivative is isolated from the concentrated solution that hasbeen obtained by the first filtration, then the filtrate is cooled so asto separate the bis (fluoroaryl) borane derivative, so that the bis(fluoroaryl) borane derivative can be isolated as a solid by performingthe second flirtation.

[0037] Thus, it is possible to isolate the fluoroaryl borane derivativeand the bis (fluoroaryl) borane derivative respectively from thesolution containing the fluoroaryl borane derivative, the bis(fluoroaryl) borane derivative, the fluorobenzene, and the hydrocarbonsolvent. Namely, it is possible to purify the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative respectively.

[0038] Therefore, according to the method of the present invention forpurifying, it is possible to readily purify the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative respectively fromthe solution containing the fluoroaryl borane derivative, the bis(fluoroaryl) borane derivative, the fluorobenzene, and the hydrocarbonsolvent. That is, according to the method of the present invention forpurifying, it is possible to purify the fluoroaryl borane derivative andthe bis (fluoroaryl) borane derivative respectively so as toindustrially use them as catalysts.

[0039] In order to solve the foregoing problems, a method of the presentinvention for purifying a fluoroaryl borane derivative and a bis(fluoroaryl) borane derivative includes the steps of: precipitating thefluoroaryl borane derivative from a solution containing the fluoroarylborane derivative, the bis (fluoroaryl) borane derivative,fluorobenzene, and a hydrocarbon solvent; performing first filtration;concentrating a filtrate that has been obtained by the first filtrationso as to remove the fluorobenzene from the solution; precipitating thebis (fluoroaryl) borane derivative from the filtrate; and performingsecond filtration, and the fluoroaryl borane derivative is representedby General Formula (1):

[0040] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), and the bis(fluoroaryl) borane derivative is represented by General Formula (2):

[0041] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), and thefluorobenzene is represented by General Formula (3):

[0042] (where each of R⁹, R¹⁰, R¹¹, R¹², and R¹³ independentlyrepresents one of a hydrogen atom, a fluorine atom, a hydrocarbon group,and an alkoxy group, and at least one of R⁹, R¹⁰, R¹¹, R¹², and R¹³represents the fluorine atom, and R⁸ represents one of a hydrogen atomand a hydrocarbon group).

[0043] According to the arrangement, it is possible to readily isolatethe fluoroaryl borane derivative and the bis (fluoroaryl) boranederivative respectively from the solution containing the fluoroarylborane derivative, the bis (fluoroaryl) borane derivative, thefluorobenzene, and the hydrocarbon solvent so as to purify them.

[0044] That is, after the fluoroaryl borane derivative is isolated as asolid by performing the first filtration, the filtrate is concentrated,so that it is possible to remove the fluorobenzene from the solution asdistillate by concentrating the solution containing the fluoroarylborane derivative, fluorobenzene, the bis (fluoroaryl) boranederivative, and the hydrocarbon solvent. Next, the fluoroaryl boranederivative is isolated from the concentrated solution that has beenobtained by the first filtration, then the filtrate is cooled asrequired so as to precipitate the bis (fluoroaryl) borane derivative, sothat the bis (fluoroaryl) borane derivative can be isolated as a solidby performing the second flirtation.

[0045] Thus, it is possible to isolate the fluoroaryl borane derivativeand the bis (fluoroaryl) borane derivative as solids respectively fromthe solution containing the fluoroaryl borane derivative, the bis(fluoroaryl) borane derivative, the fluorobenzene, and the hydrocarbonsolvent. Namely, it is possible to purify the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative respectively.

[0046] Therefore, according to the method of the present invention forpurifying, it is possible to readily purify the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative respectively fromthe solution containing the fluoroaryl borane derivative, the bis(fluoroaryl) borane derivative, the fluorobenzene, and the hydrocarbonsolvent. That is, according to the method of the present invention forpurifying, it is possible to purify the fluoroaryl borane derivative andthe bis (fluoroaryl) borane derivative respectively so as toindustrially use them as catalysts.

[0047] In order to solve the foregoing problems, a method of the presentinvention for purifying the fluoroaryl borane derivative and the bis(fluoroaryl) borane derivative is arranged so that a solution containingthe fluoroaryl borane derivative and the bis (fluoroaryl) boranederivative is obtained by reacting tris (fluoroaryl) borane with acompound (5) in a molar ratio from 1:1.9 to 1:5 in a hydrocarbonsolvent, and the tris (fluoroaryl) borane is represented by GeneralFormula (4):

[0048] (where each of R¹, R², R³, R⁴, and R5 independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom), and the compound is represented by General Formula (5):

R⁶—MR¹⁴(R⁷)n  (5)

[0049] (where each of R⁶, R⁷, and R¹⁴ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5a or Group 6a, and n represents 0 or 1).

[0050] According to the arrangement, it is possible to selectivelyobtain the fluoroaryl borane derivative by reacting the tris(fluoroaryl) borane with the compound (5) in the hydrocarbon solvent.That is, it is possible to selectively obtain the fluoroaryl boranederivative by reacting the tris (fluoroaryl) borane with the compound(5) in a molar ratio from 1:1.9 to 1:5 in the hydrocarbon solvent.

[0051] Therefore, according to the reaction, it is possible to obtainthe solution containing much fluoroaryl borane derivative as thesolution containing the fluoroaryl borane derivative and the bis(fluoroaryl) borane derivative. After the fluoroaryl borane derivativeis isolated from the solution by the first filtration, a crystal of thebis (fluoroaryl) borane derivative is separated from the filtrate as aprecipitated deposit, so that it is possible to isolate the bis(fluoroaryl) borane derivative as a solid by the second filtration.Furthermore, since the solution contains a large quantity of fluoroarylborane derivative, it is possible to isolate the fluoroaryl boranederivative efficiently.

[0052] Thus, it is possible to obtain the solution containing muchfluoroaryl borane derivative as a solution containing the fluoroarylborane derivative and the bis (fluoroaryl) borane derivative, so that itis possible to isolate the fluoroaryl borane derivative and the bis(fluoroaryl) borane derivative respectively, that is, it is possible topurify the fluoroaryl borane derivative and the bis (fluoroaryl) boranederivative respectively. Moreover, it is possible to obtain thefluoroaryl borane derivative with a high isolation yield.

[0053] Thus, according to the method of the present invention forpurifying, it is possible to readily isolate and purify the fluoroarylborane derivative and the bis (fluoroaryl) borane derivativerespectively from the reaction mixture containing the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative without includingindustrially undesirable steps such as drying up the solvent. Moreover,it is possible to obtain the fluoroaryl borane derivative with a highisolation yield. That is, according to the method of the presentinvention for purifying, it is possible to purify the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative respectively so asto enable the fluoroaryl borane derivative in particular to be used as acatalyst etc. industrially.

[0054] In order to solve the foregoing problems, a method of the presentinvention for purifying the fluoroaryl borane derivative and the bis(fluoroaryl) borane derivative is arranged so that a solution containingthe fluoroaryl borane derivative and the bis (fluoroaryl) boranederivative is obtained by reacting tris (fluoroaryl) borane with acompound (5) in a molar ratio from 1:0.9 to 1:1.1 in a hydrocarbonsolvent, and the tris (fluoroaryl) borane is represented by GeneralFormula (4):

[0055] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom), and the compound is represented by General Formula (5):

R⁶—MR¹⁴(R⁷)n  (5)

[0056] (where each of R⁶, R⁷, and R¹⁴ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5a or Group 6a, and n represents 0 or 1).

[0057] According to the arrangement, it is possible to selectivelyobtain the bis (fluoroaryl) borane derivative by reacting the tris(fluoroaryl) borane with the compound (5) in the hydrocarbon solvent.That is, it is possible to selectively obtain the bis (fluoroaryl)borane derivative by reacting the tris (fluoroaryl) borane with thecompound (5) in a molar ratio from 1:0.9 to 1:11 in the hydrocarbonsolvent.

[0058] Therefore, according to the reaction, it is possible to obtainthe solution containing a large quantity of bis (fluoroaryl) boranederivative as the solution containing fluoroaryl borane derivative andthe bis (fluoroaryl) borane derivative. After the fluoroaryl boranederivative is isolated from the solution by the first filtration, acrystal of the bis (fluoroaryl) borane derivative is separated from thefiltrate as a precipitated deposit, so that it is possible to isolatethe bis (fluoroaryl) borane derivative as a solid by the secondfiltration. Furthermore, since the solution contains a large quantity ofbis (fluoroaryl) borane derivative, it is possible to isolate thefluoroaryl borane derivative efficiently.

[0059] Thus, it is possible to obtain the solution containing a largequantity of bis (fluoroaryl) borane derivative as a solution containingthe fluoroaryl borane derivative and the bis (fluoroaryl) boranederivative, so that it is possible to isolate the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative respectively, thatis, it is possible to purify the fluoroaryl borane derivative and thebis (fluoroaryl) borane derivative respectively. Moreover, it ispossible to obtain the fluoroaryl borane derivative with a highlyisolated yield.

[0060] Thus, according to the method of the present invention forpurifying, it is possible to readily isolate and purify the fluoroarylborane derivative and the bis (fluoroaryl) borane derivativerespectively from the reaction mixture containing the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative without includingindustrially undesirable steps such as drying up the solvent. Moreover,it is possible to obtain the bis (fluoroaryl) borane derivative with ahighly isolated yield. That is, according to the method of the presentinvention for purifying, it is possible to purify the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative respectively so asto enable the bis (fluoroaryl) borane derivative in particular to beused as a catalyst etc. industrially.

[0061] In the method of the present invention for purifying thefluoroaryl borane derivative and the bis (fluoroaryl) borane derivative,it is preferable that the hydrocarbon solvent is substantially analiphatic hydrocarbon solvent.

[0062] According to the arrangement, it is possible to increase theyield at which the fluoroaryl borane derivative and the bis (fluoroaryl)borane derivative are isolated.

[0063] That is, since the solubility of bis (fluoroaryl) boranederivative with respect to the aliphatic hydrocarbon solvent is lowunder a low temperature condition, it is possible to precipitate a largepart of the bis (fluoroaryl) borane derivative in the filtrate in a casewhere the hydrocarbon solvent is the aliphatic hydrocarbon solvent.Thus, it is possible to obtain the bis (fluoroaryl) borane derivativewith a high isolation yield by the second filtration.

[0064] A fluoroaryl borane derivative of the present invention is asolid represented by General Formula (1):

[0065] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), wherein thefluoroaryl borane derivative contains a bis (fluoroaryl) boranederivative so that the content of the bis (fluoroaryl) borane is notmore than 1% by weight, and the bis (fluoroaryl) borane derivative isrepresented by General Formula (2):

[0066] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1).

[0067] It is preferable that purity of the fluoroaryl borane derivativeis not less than 90%.

[0068] According to the arrangement, since the purity of the fluoroarylborane derivative is high, it is possible to industrially use it morepreferably as a catalyst.

[0069] A bis (fluoroaryl) borane derivative of the present invention isa solid represented by General Formula (2):

[0070] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), wherein thebis (fluoroaryl) borane derivative contains a fluoroaryl boranederivative so that the content of the fluoroaryl borane derivative isnot, more than 1% by weight, and the bis (fluoroaryl) borane isrepresented by General Formula (2):

[0071] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1).

[0072] It is preferable that purity of the bis (fluoroaryl) boranederivative is not less than 95%.

[0073] According to the arrangement, since the purity of the bis(fluoroaryl) borane derivative is high, it is possible to industriallyuse it more preferably as a catalyst.

[0074] In order to solve the foregoing problems, a method of the presentinvention for producing a fluoroaryl borane derivative includes the stepof reacting tris (fluoroaryl) borane with a compound (5) in a molarratio from 1:1.9 to 1:5 in a hydrocarbon solvent, and the tris(fluoroaryl) borane is represented by General Formula (4):

[0075] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom), and the compound is represented by General Formula (5):

R⁶—MR¹⁴(R⁷)n  (5)

[0076] (where each of R⁶, R⁷, and R¹⁴ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5a or Group 6a, and n represents 0 or 1).

[0077] According to the arrangement, it is possible to selectivelyobtain the fluoroaryl borane derivative by reacting the tris(fluoroaryl) borane with the compound (5) in the hydrocarbon solvent.That is, it is possible to selectively obtain the fluoroaryl boranederivative by reacting the tris (fluoroaryl) borane with the compound(5) in a molar ratio from 1:1.9 to 1:5.0 in the hydrocarbon solvent.

[0078] In a method of the present invention for producing the fluoroarylborane derivative, it is preferable that not more than 1 weight % bis(fluoroaryl) borane derivative is contained, and the bis (fluoroaryl)borane derivative is represented by General Formula (2):

[0079] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1).

[0080] It is preferable that purity of the fluoroaryl borane derivativeis not less than 90%.

[0081] According to the arrangement, since the purity of the fluoroarylborane derivative is high, it is possible to industrially use it morepreferably as a catalyst.

[0082] The following description will give fuller understanding of stillanother object, characteristic, and superiority of the presentinvention. Further, the benefit of the present invention will beclarified by the following description.

[0083] A method for producing a fluoroaryl borane derivative and a bis(fluoroaryl) borane derivative that should be purified by the method ofthe present invention for purifying is not particularly limited, butvarious methods can be employed. It is possible to produce thefluoroaryl borane derivative and the bis (fluoroaryl) borane derivativeby reacting tris (fluoroaryl) borane with a compound (5) in ahydrocarbon solvent, and the tris (fluoroaryl) borane is represented byGeneral Formula (4):

[0084] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom), and the compound is represented by General Formula (5):

R⁶—MR¹⁴(R⁷)n  (5)

[0085] (where each of R⁶, R⁷, and R¹⁴ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5a or Group 6a, and n represents 0 or 1).

[0086] It is preferable to use such reaction that, for example, water isused as the compound (5) so as to hydrolyze the tris (fluoroaryl)borane. Note that, although it is possible to hydrolyze the tris(fluoroaryl) borane in the presence of hydrate such as aluminium sulfate18 hydrate upon hydrolyzing, there occur such problems that: reactionprocess is complicated and it is required to remove generated salt suchas aluminium sulfate. Thus, in the embodiments of the present invention,it is preferable to perform hydrolysis in the presence of water, and itis more preferable to perform the hydrolysis so that hydrate salt doesnot coexist. Here, the hydrolysis performed so that hydrate salt doesnot coexist is such that: an amount of hydrate salt which is allowed toexist is 0 to 5%, preferably 0 to 2%, and more preferably 0 to 1%.

[0087] As methods for mixing the tris (fluoroaryl) borane and thecompound (5) in the hydrocarbon solvent, for example, there are thefollowing methods: the tris (fluoroaryl) borane is dissolved in thehydrocarbon solvent so as to make a solution, and the compound (5) isadded to the solution so as to be mixed, the tris (fluoroaryl) boraneand the compound (5) are added to and mixed in the hydrocarbon solventat the same time, and (c) the tris (fluoroaryl) borane is added to andmixed in the hydrocarbon solvent in which the compound (5) has beenadded.

[0088] A temperature at which the tris (fluoroaryl) borane and thecompound (5) are mixed in the hydrocarbon solvent preferably ranges from−100° C. to 300° C., and more preferably ranges from 0° C. to 200° C.

[0089] Note that, in the method for producing a fluoroaryl boranederivative and a bis (fluoroaryl) borane derivative that should bepurified by the method for purifying according to the present invention,it is possible to selectively produce either the fluoroaryl boranederivative or the bis (fluoroaryl) borane derivative.

[0090] To obtain the fluoroaryl borane derivative represented by GeneralFormula (1), for example, to obtain a pentafluorophenyl boronic acidetc. with high purity, the following reaction condition for obtainingthe highly-purified fluoroaryl borane derivative represented by GeneralFormula (1) and the method of the present invention for purifying areemployed together, so that it is possible to selectively produce thepentafluorophenyl boronic acid as the fluoroaryl borane derivativerepresented by General Formula (1), more easily.

[0091] For example, in a case where water is used as the compound (5) soas to perform hydrolysis while using the tris (pentafluorophenyl) boraneas the tris (fluoroaryl) borane, water is used excessively with respectto the tris (pentafluorophenyl) borane, more specifically, the tris(pentafluorophenyl) borane and water are used in a molar ratio from1:1.9 to 1:5.0, so that it is possible to selectively obtain thepentafluorophenyl boronic acid.

[0092] If the molar ratio of water with respect to the tris (fluoroaryl)borane is less than 1.9, more bis (fluoroaryl) borane derivative isgenerated, so that a yield of the fluoroaryl borane derivativedecreases. Further, if the molar ratio of water with respect to the tris(fluoroaryl) borane is more than 5.0, reaction rate becomes extremelyslow, so that this is industrially undesirable.

[0093] Contrary, to obtain the bis (fluoroaryl) borane derivativerepresented by General Formula (2), for example, to obtain ahighly-purified bis (pentafluorophenyl) borinic acid etc., it ispreferable that the following step is employed as a preceding step incombination with the method of the present invention for purifying.

[0094] The following reaction condition for obtaining thehighly-purified bis (fluoroaryl) borane derivative represented byGeneral Formula (2) and the method of the present invention forpurifying are employed together, so that it is possible to selectivelyproduce the bis (pentafluorophenyl) borinic acid as the bis (fluoroaryl)borane derivative represented by General Formula (2), more easily.

[0095] For example, in a case where water is used as the compound (5) soas to perform hydrolysis while using the tris (pentafluorophenyl) boraneas the tris (fluoroaryl) borane, the tris (pentafluorophenyl) borane andwater are substantially equalized in a molar ratio, more specifically,the tris (pentafluorophenyl) borane and water are used in a molar ratiofrom 1:0.9 to 1:1.1, so that it is possible to selectively obtain thebis (pentafluorophenyl) borinic acid.

[0096] If the molar ratio of water with respect to the tris (fluoroaryl)borane is less than 0.9, a conversion of the tris (fluoroaryl) boranederivative decreases, so that a yield of the bis (fluoroaryl) boranederivative decreases. Further, if the molar ratio of water with respectto the tris (fluoroaryl) borane is more than 1.1, more fluoroaryl boranederivative is generated, so that the yield of the bis (fluoroaryl)borane derivative is low.

[0097] That is, to efficiently obtain the fluoroaryl borane derivativerepresented by General Formula (1), it is preferable that the tris(fluoroaryl) borane and the compound (5) are used in a molar ratio from1:1.9 to 1:5.0. Further, to efficiently obtain the bis fluoroaryl boranederivative represented by General Formula (2), it is preferable that thetris (fluoroaryl) borane and the compound (5) are used in a molar ratiofrom 1:0.9 to 1:1.1.

[0098] In the present invention, it is preferable to employ thefollowing producing method for selectively obtaining the fluoroarylborane derivative represented by General Formula (1).

[0099] A method for producing a fluoroaryl borane derivative accordingto the present invention includes the step of reacting a tris(fluoroaryl) borane with a compound (5) in a molar ratio from 1:1.9 to1:5 in a hydrocarbon solvent, and the tris (fluoroaryl) borane isrepresented by General Formula (4):

[0100] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom), and the compound is represented by General Formula (5):

R⁶—MR¹⁴(R⁷)n  (5)

[0101] (where each of R⁶, R⁷, and R¹⁴ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5a or Group 6a, and n represents 0 or 1).

[0102] It is preferable that not more than 1 weight % bis (fluoroaryl)borane derivative represented by General Formula (2) is contained in thefluoroaryl borane derivative, represented by General Formula (1), whichis obtained by the method for selectively obtaining the fluoroarylborane derivative. It is more preferable that the purity of thefluoroaryl borane derivative represented by General Formula (1) is notless than 90%.

[0103] In the reaction of the tris (fluoroaryl) borane and the compound(5) in the hydrocarbon solvent, it is preferable to set a using amountof the hydrocarbon solvent so that the concentration of the tris(fluoroaryl) borane ranges from 0.1 weight % to 80 weight %, and it ismore preferable to set the using amount so that the concentration of thetris (fluoroaryl) borane ranges from 1 weight % to 30 weight %. It ispreferable that a reaction temperature in the reaction ranges from 0° C.to 300° C., and it is more preferable that the reaction temperatureranges from 50° C. to 200° C.

[0104] The reaction mixture obtained by the method, that is, thesolution containing the fluoroaryl borane derivative as an object, thebis (fluoroaryl) borane derivative, and the hydrocarbon solvent alsocontains the fluorobenzene as a byproduct so that the fluorobenzene isdissolved. When the fluoroaryl borane derivative and the bis(fluoroaryl) borane derivative are precipitated and filtratedrespectively, it is possible to obtain the fluoroaryl borane derivativeand the bis (fluoroaryl) borane derivative as solid respectively. Sincethe fluoroaryl borane derivative and the bis (fluoroaryl) boranederivative dissolve in the fluorobenzene, the fluorobenzene may beremoved as required.

[0105] A method for purifying a fluoroaryl borane derivative and a bis(fluoroaryl) borane derivative according to the present inventionincludes the steps of: precipitating the fluoroaryl borane derivativefrom a solution containing the fluoroaryl borane derivative, the bis(fluoroaryl) borane derivative, and a hydrocarbon solvent; performingfirst filtration; precipitating the bis (fluoroaryl) borane derivativeby cooling a filtrate that has been obtained by the first filtration;and performing second filtration. Further, a method for purifying afluoroaryl borane derivative and a bis (fluoroaryl) borane derivativeaccording to the present invention includes the steps of: concentratinga solution containing the fluoroaryl borane derivative, the bis(fluoroaryl) borane derivative, fluorobenzene, and a hydrocarbonsolvent; precipitating the fluoroaryl borane derivative after removingthe fluorobenzene from the solution; performing first filtration;precipitating the bis (fluoroaryl) borane derivative by cooling afiltrate that has been obtained by the first filtration; performingsecond filtration. Further, a method for purifying a bis (fluoroaryl)borane derivative according to the present invention includes the stepsof: precipitating a fluoroaryl borane derivative after removingfluorobenzene from a solution containing the fluoroaryl boranederivative, the bis (fluoroaryl) borane derivative, the fluorobenzene,and a hydrocarbon solvent; performing first filtration; concentrating afiltrate that has been obtained by the first filtration; removing thefluorobenzene; precipitating the bis (fluoroaryl) borane derivative fromthe filtrate; and performing second filtration.

[0106] Furthermore, a method for purifying a fluoroaryl boranederivative and a bis (fluoroaryl) borane derivative according to thepresent invention includes the steps of: precipitating the fluoroarylborane derivative after removing fluorobenzene from a solutioncontaining the fluoroaryl borane derivative, the bis (fluoroaryl) boranederivative, the fluorobenzene, and a hydrocarbon solvent; performingfirst filtration; precipitating the bis (fluoroaryl) borane derivativeby cooling a filtrate that has been obtained by the first filtration;and performing second filtration.

[0107] A fluoroaryl borane derivative that should be purified by themethod for purifying according to the present invention is a compoundrepresented by General Formula (1):

[0108] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1).

[0109] In the general formula, specifically, the hydrocarbon group forthe substitutional groups represented by R¹, R², R³, R⁴, and R⁵represents an aryl group such as a phenyl group, a straight or branchedalkyl group containing 1 to 12 carbon atoms, a cyclic alkyl groupcontaining 3 to 12 carbon atoms, a straight or branched alkenyl groupcontaining 2 to 12 carbon atoms, and a cyclic alkenyl group containing 3to 12 carbon atoms. Examples of the alkyl group are, specifically, amethyl group, an ethyl group, a propyl group, an isopropyl group, abutyl group, an isobutyl group, a t-butyl group, a pentyl group, anisopentyl group, a t-pentyl group, a hexyl group, an octyl group, acyclopropyl group, a cyclobtyl group, a cyclopentyl group, a cyclohexylgroup, and a methylcyclohexyl group. An example of the alkenyl group is,specifically, an allyl group.

[0110] Note that, the hydrocarbon group may further include a functionalgroup including an atom that is inert to the purification (treatment) ofthe present invention, for example, a fluorine atom, a nitrogen atom, anoxygen atom, a sulfur atom, that is, an inert functional group. Examplesof the functional group are a methoxy group, a methylthio group, anN,N-dimethylamino group, an o-anis group, a p-anis group, atrimethylsilyloxy group, a dimethyl-t-butylsilyloxy group, and atrifluoromethyl group.

[0111] In the general formula, the alkoxy group for the substitutionalgroup represented by R¹, R², R³, R⁴, and R⁵ is represented by GeneralFormula (A):

—ORa  (A)

[0112] (where Ra represents a hydrocarbon group). In the generalformula, the hydrocarbon represented by Ra specifically represents anaryl group such as a phenyl group, a straight or branched alkyl groupcontaining 1 to 12 carbon atoms, a cyclic alkyl group containing 3 to 12carbon atoms, a straight or branched alkenyl group containing 2 to 12carbon atoms, a cyclic alkenyl group containing 3 to 12 carbon atoms.Note that, the hydrocarbon group may further include a functional groupincluding an atom that is inert to the purification of the presentinvention. Examples of the alkoxy group represented by General Formula(A) are, specifically, a methoxy group, an ethoxy group, an n-propoxygroup, an isopropoxy group, an n butoxy group, an isobutoxy group, asec-butoxy group, a t-butoxy group, a cyclohexyloxy group, an allyloxygroup, and a phenoxy group.

[0113] In the general formula, an example of the hydrocarbon grouprepresented by R⁶ and R⁷ is a substitutional group similar to thesubstitutional group of the hydrocarbon group represented by R¹, R², R³,R⁴, and R⁵. In the general formula, a nitrogen atom or an oxygen atom isparticularly preferable out of Group 5B (Group 15 in a long-period type)or Group 6B (Group 16 in a long-period type) of a substitutional grouprepresented by M.

[0114] Thus, examples of the fluoroaryl borane derivative are,specifically, a p-fluorophenyl boronic acid, a 2,6-difluorophenylboronic acid, a 2,4,6-trifluorophenyl boronic acid, a2,3,5,6-tetrafluorophenyl boronic acid, a pentafluorophenyl boronicacid, and the like.

[0115] Note that, it is preferable that the purity of the fluoroarylborane derivative that should be purified by the method of the presentinvention for purifying is not less than 90%. More preferably, thepurity is not less than 95%. Still more preferably, the purity is notless than 98%. In this case, an amount of the bis (fluoroaryl) boranederivative contained as a byproduct is not more than 10%, morepreferably not more than 5%, and still more preferably not more than 2%.

[0116] The bis (fluoroaryl) borane derivative that should be purified bythe method for purifying according to the present invention is acompound represented by General Formula (2):

[0117] (where each of R¹, R², R³, R⁴, and R⁵ independently representsone of a hydrogen atom, a fluorine atom, a hydrocarbon group, and analkoxy group, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1).

[0118] In the general formula, an example of the hydrocarbon grouprepresented by R¹, R², R³, R⁴ and R⁵ is, specifically, a substitutionalgroup similar to the substitutional group of the hydrocarbon group andthe alkoxy group that are represented by R¹, R², R³, R⁴, and R⁵. In thegeneral formula, an example of the hydrocarbon group represented by R⁶and R⁷ is, specifically, a substitutional group similar to thesubstitutional group of the hydrocarbon group represented by R¹, R², R³,R⁴, and R⁵. In the general formula, a nitrogen atom or an oxygen atom isparticularly preferable out of Group 5B (Group 15 in a long-period type)or Group 6B (Group 16 in a long-period type) of a substitutional grouprepresented by M.

[0119] Thus, examples of the bis (fluoroaryl) borane derivative are,specifically, a bis (p-fluorophenyl) borinic acid, a bis(2,6-difluorophenyl) borinic acid, a bis (2,4,6-trifluorophenyl) borinicacid, a bis (2,3,5,6-tetrafluorophenyl) borinic acid, a bis(pentafluorophenyl) borinic acid, and the like.

[0120] It is preferable that the purity of the bis (fluoroaryl) boranederivative that should be purified by the method of the presentinvention is not less than 95%. More preferably, the purity is not lessthan 98%. In this case, an amount of the fluoroaryl borane derivativewhich exists in the bis (fluoroaryl) borane derivative is not more than2%, more preferably not more than 1%, and still more preferably not morethan 0.8%.

[0121] The fluorobenzene that should be removed by the method accordingto the present invention for purifying is a compound represented byGeneral Formula (3):

[0122] (where each of R⁹, R¹⁰, R¹¹, R¹², and R¹³ independentlyrepresents one of a hydrogen atom, a fluorine atom, a hydrocarbon group,and an alkoxy group, and at least one of R⁹, R¹⁰, R¹¹, R¹², and R¹³represents the fluorine atom, and R⁸ represents one of a hydrogen atomand a hydrocarbon group).

[0123] In the general formula, an example of the hydrocarbon group andthe alkoxy group of the substitutional group represented by R⁹, R¹⁰,R¹¹, R¹², and R¹³ is, specifically, a substitutional group similar tothe substitutional group of the hydrocarbon group and the alkoxy groupthat are represented by R¹, R², R³, R⁴, and R⁵. In the general formula,an example of the hydrocarbon group represented by R⁸ is, specifically,a substitutional group similar to the substitutional group of thehydrocarbon group represented by R¹, R², R³, R⁴, and R⁵.

[0124] Thus, examples of the fluorobenzene are, specifically, afluorobenzene, a 2,6-difluorobenzene, a 2,4,6-trifluorobenzene, a2,3,5,6-tetrafluorobenzene, a pentafluorobenzene, and the like.

[0125] Examples of the hydrocarbon solvent contained in the solutioncontaining the fluoroaryl borane derivative and the bis (fluoroaryl)borane derivative are an aliphatic hydrocarbon solvent such as asaturated hydrocarbon solvent, unsaturated hydrocarbon solvent, andalicyclic hydrocarbon solvent, and an aromatic hydrocarbon solvent.

[0126] As the hydrocarbon solvent, the aliphatic hydrocarbon solvent ismore preferable. Specifically, examples of the hydrocarbon solvent are2,2-dimethylbutane, 2,3-dimethylbutane, 2,2,3-trimethylbutan, pentane,2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane,3,3-dimethylpentane, 2-methylpentane, 3-methylpentane,2,2,4-trimethylpentane, 2,3,4-trimethylpentane, hexan,2-methylhexane,3-methylhexane, 2,2-dimehtylhexane, 2,4-dimethylhexane,2,5-dimetylhexane, 3,4-dimethylhexane, heptane, 2-methylheptane,3-methylheptane, 4-methylheptane, 2,3-dimethylheptane, octane, nonan,decane, undecane, dodecane, tridecane, pentene, hexen, heptene, octene,cyclopentane, methylcyclopentane, ethylcyclopentane, cyclohexane,methylcyclohexane, 1,2,dimethylcyclohexane, 1,3-dimethylcyclohexane,1,4-dimethylcyclohexane, ethylcyclohexane, cycloheptane, cyclooctane,cyclopentene, and cyclohexene. One of those hydrocarbon solvents may beused solely or more than two of those hydrocarbon solvents may beappropriately mixed and used. Moreover, commercial hydrocarbon solventssuch as IsoparC, IsoparE, and IsoparG (any of them are RegisteredTrademarks) supplied from Exxon Corp. may be used.

[0127] It is preferable that the hydrocarbon solvent is substantially analiphatic hydrocarbon solvent. For example, bis (pentafluorophenyl)borinic acid, which is a bis (fluoroaryl) borane derivative, isrelatively soluble to the aromatic hydrocarbon solvent such as toluene.Thus, bis (pentafluorophenyl) borinic acid has a low yield whenisolation of bis (pentafluorophenyl) borinic acid is carried out byfiltration after concentration of a reaction mixture, in case thearomatic hydrocarbon solvent is used as a solvent. Because of this, itis necessary to have a step of concentrating and drying up the reactionmixture by distilling off the solvent, in order to have a high yield forisolation of the bis (pentafluorophenyl) borinic acid.

[0128] On the other hand, the bis (fluoroaryl) borane derivative has alow solubility for the aliphatic hydrocarbon solvent. Thus, in case thehydrocarbon solvent is substantially an aliphatic hydrocarbon solvent,it is possible to have a high yield of the bis (fluoroaryl) boranederivative by the step of performing the filtration after cooling thereaction mixture.

[0129] Further, the foregoing hydrocarbon solvent may be a hydrocarbonsolvent used to prepare the fluoroaryl borane derivative or the bis(fluoroaryl) borane derivative by reacting the tris (fluoroaryl) boranerepresented by General Formula (4) with the compound represented byGeneral Formula (5).

[0130] Note that, in the present invention, the wording “the hydrocarbonsolvent is substantially an aliphatic hydrocarbon solvent” means that aratio of the aliphatic hydrocarbon solvent in the hydrocarbon solvent iswithin a range of 80% by weight to 100% by weight, and more preferablywithin a range of 95% by weight to 100% by weight.

[0131] In the method for purifying according to the present invention,the solution (hereinbelow, sometimes referred to merely as solution A)containing the fluoroaryl borane derivative, the bis (fluoroaryl) boranederivative, and the hydrocarbon solvent is subjected to the firstfiltration after precipitating the fluoroaryl borane derivative attemperature at which the fluoroaryl borane derivative is precipitated,and the filtrate obtained by the first filtration is cooled afterisolating the fluoroaryl borane derivative as a precipitated deposit,and the cooled filtrate is subjected to the second filtration afterprecipitating the bis (fluoroaryl) borane derivative, and the bis(fluoroaryl) borane derivative is isolated as a solid, so that thefluoroaryl borane derivative and the bis (fluoroaryl) borane derivativeare purified.

[0132] The temperature at which the fluoroaryl borane derivative isseparated from the solution A is set so that the fluoroaryl boranederivative is sufficiently precipitated, and it is more preferable thatthe temperature is set so that the bis (fluoroaryl) borane derivative isnot precipitated, or the bis (fluoroaryl) borane derivative is hardlyprecipitated. Specifically, it is preferable that the temperature iswithin a range of −30° C. to 300° C., and more preferably within a rangeof 0° C. to 200° C.

[0133] The fluoroaryl borane derivative may be isolated from thesolution A as follows: after the fluoroaryl borane derivative isprecipitated from the solution A by distilling off the hydrocarbonsolvent as required, the first filtration is performed so as to isolatethe fluoroaryl borane derivative from the solution A.

[0134] As a method for distilling off the hydrocarbon solvent,specifically, the following methods may be employed: the solution A isheated under an ordinary pressure (atmospheric pressure), or thesolution A is heated under a reduced pressure or a pressurizationcondition. In this way, the method for distilling off the hydrocarbonsolvent is not particularly limited. Further, the heating temperature isset to be more than each boiling temperature of the hydrocarbon solventat each pressure.

[0135] Note that, the hydrocarbon solvent in the filtrate obtained bythe first filtration may be removed as required before the bis(fluoroaryl) borane derivative is precipitated by cooling the filtrate.That is, the bis (fluoroaryl) borane derivative may be isolated as asolid as follows: after the hydrocarbon solvent in the filtrate obtainedby the first filtration is distilled off, the filtrate in which thehydrocarbon solvent has been partially distilled off is cooled so as toprecipitate the bis (fluoroaryl) borane derivative, and the bis(fluoroaryl) borane derivative is isolated as a solid by performing thesecond filtration.

[0136] The temperature at which the filtrate is cooled so as toprecipitate the bis (fluoroaryl) borane derivative may be set so thatthe bis (fluoroaryl) borane derivative is sufficiently precipitated.Specifically, the temperature preferably is in a range from −50° C. to200° C., more preferably from −30° C. to 100° C. Time taken to cool thefiltrate may be suitably set according to an amount etc. of the reactionmixture.

[0137] Note that, the following step may be employed: the filtrateobtained by the second filtration is further concentrated and the bis(fluoroaryl) borane derivative is precipitated so as to filtrate theseparated bis (fluoroaryl) borane derivative, so that the bis(fluoroaryl) borane derivative contained in the filtrate is isolated.The concentration of the filtrate is performed by removing thehydrocarbon solvent from the filtrate. Specifically, the concentrationof the filtrate can be performed in the same manner as in distilling offthe hydrocarbon solvent from the solution A.

[0138] Note that, the filtrate obtained by the second filtration, or afiltrate obtained by concentrating that filtrate so as to remove theprecipitated bis (fluoroaryl) borane derivative may be reused (recycled)as a hydrocarbon solvent.

[0139] By performing the foregoing steps, it is possible to precipitatethe fluoroaryl borane derivative as a solid. The fluoroaryl boranederivative can be isolated by performing the first filtration. Further,by cooling the filtrate after the first filtration, the bis (fluoroaryl)borane derivative can be precipitated as a solid. By performing thesecond filtration, the bis (fluoroaryl) borane derivative can beisolated. That is, it is possible to obtain the high-purity fluoroarylborane derivative and bis (fluoroaryl) borane derivative containing noimpurity with ease and at a low cost.

[0140] A method according to the present invention for purifying afluoroaryl borane derivative and a bis (fluoroaryl) borane derivativeincludes the steps of: concentrating a solution (hereinbelow, sometimesreferred to merely as solution B) containing the fluoroaryl boranederivative, the bis (fluoroaryl) borane derivative, fluorobenzene, and ahydrocarbon solvent; removing the fluorobenzene from the solution;precipitating the fluoroaryl borane derivative at temperature at whichthe fluoroaryl borane derivative is precipitated; performing firstfiltration; isolating the fluoroaryl borane derivative; cooling afiltrate that has been obtained by the first filtration; precipitatingthe bis (fluoroaryl) borane derivative; performing second filtration;and isolating the bis (fluoroaryl) borane derivative as a solid.

[0141] It is possible to concentrate the solution B by distilling offthe fluorobenzene and/or the hydrocarbon solvent from the solution B. Asa method for distilling off the hydrocarbon solvent, specifically, thefollowing methods may be employed: the solution B is heated under anordinary pressure (atmospheric pressure), or the solution B is heatedunder a reduced pressure or a pressurization condition. In this way, themethod is not particularly limited. Further, the heating temperature isset to be more than each boiling temperature of the fluorobenzene ateach pressure. Time taken to concentrate the reaction mixture may besuitably set according to an amount etc. of the reaction mixture.

[0142] The concentrated solution obtained by concentrating the solutionB substantially contains the fluoroaryl borane derivative, the bis(fluoroaryl) borane derivative, and the hydrocarbon solvent.

[0143] Next, the first filtration is performed after precipitating thefluoroaryl borane derivative from the concentrated solution, so that thefluoroaryl borane derivative can be isolated and purified. The secondfiltration is performed after the filtrate is further cooled so as toprecipitate the bis (fluoroaryl) borane derivative, so that the bis(fluoroaryl) borane derivative can be isolated as a solid and can bepurified. Note that, the foregoing first and second filtration areperformed as in the filtration of the solution A.

[0144] Note that, before the filtrate obtained by the first filtrationis cooled so as to precipitate the bis (fluoroaryl) borane derivative,the hydrocarbon solvent in the filtrate may be distilled off asrequired. That is, the following step may be employed: after distillingoff the hydrocarbon solvent in the filtrate obtained by the firstfiltration, the filtrate with the hydrocarbon solvent partiallydistilled off is cooled, and the bis (fluoroaryl) borane derivative isprecipitated so as to perform the second filtration, so that the bis(fluoroaryl) borane derivative is isolated as a solid.

[0145] Further, the following step may be employed: the filtrateobtained by the second filtrate is further concentrated, and the bis(fluoroaryl) borane derivative is precipitated, and the precipitated bis(fluoroaryl) borane derivative is filtrated, so that the bis(fluoroaryl) borane derivative contained in the filtrate is isolated.The concentration of the filtrate is performed by removing thehydrocarbon solvent from the filtrate. Specifically, the concentrationcan be performed in the same manner as in distilling off the hydrocarbonsolvent from the solution A.

[0146] Note that, the filtrate obtained by the second filtration, or afiltrate obtained by concentrating that filtrate so as to remove theprecipitated bis (fluoroaryl) borane derivative may be reused (recycled)as a hydrocarbon solvent.

[0147] By performing the foregoing steps, after distilling off thefluorobenzene from the solution, it is possible to precipitate thefluoroaryl borane derivative and to isolate the fluoroaryl boranederivative so as to perform the first filtration. Further, by coolingthe filtrate that has been obtained by the first filtration, the bis(fluoroaryl) borane derivative can be isolated as a solid. That is, itis possible to obtain the high-purity fluoroaryl borane derivative andbis (fluoroaryl) borane derivative containing no impurity with ease andat a low cost.

[0148] A method according to the present invention for purifying afluoroaryl borane derivative and a bis (fluoroaryl) borane derivativeincludes the steps of: precipitating the fluoroaryl borane derivative attemperature at which the fluoroaryl borane derivative is precipitatedfrom a solution (solution B) containing the fluoroaryl boranederivative, the bis (fluoroaryl) borane derivative, fluorobenzene, and ahydrocarbon solvent; performing first filtration; isolating thefluoroaryl borane derivative; concentrating a filtrate that has beenobtained by the first filtration; removing the fluorobenzene from thefiltrate; performing second filtration; isolating the bis (fluoroaryl)borane derivative precipitated in the filtrate that has beenconcentrated.

[0149] The first filtration is performed after the fluoroaryl boranederivative has been precipitated, so that it is possible to isolate thefluoroaryl borane derivative from the solution B. Note that, the firstfiltration is performed specifically in the same manner as in thesolution A.

[0150] By concentrating the filtrate obtained by the first filtration,it is possible to remove the fluorobenzene from the filtrate asdistillate. Note that, the step for concentrating the filtrate isperformed specifically in the same manner as in the solution B.

[0151] The concentration of the bis (fluoroaryl) borane derivative inthe filtrate becomes high by concentrating the filtrate obtained by thefirst filtration and the concentration exceeds the solubility, so that acrystal is precipitated. Further, to precipitate the bis (fluoroaryl)borane derivative, the concentrated filtrate may be cooled. The materialprecipitated from the filtrate is subjected to the second filtration, sothat it is possible to readily isolate the bis (fluoroaryl) boranederivative as a solid. Note that, the second filtration is performedspecifically in the same manner as in the solution A.

[0152] Further, the following step may be employed: the filtrateobtained by the second filtration is further concentrated, and the bis(fluoroaryl) borane derivative is precipitated, and the precipitation ofbis (fluoroaryl) borane derivative is filtrated, so that the bis(fluoroaryl) borane derivative contained in the filtrate is isolated.The concentration of the filtrate is performed by removing thehydrocarbon solvent from the filtrate. Specifically, the concentrationis performed in the same manner as in distilling off the hydrocarbonsolvent from the solution A.

[0153] Note that, the filtrate obtained by the second filtration, or afiltrate obtained by concentrating that filtrate so as to remove theprecipitated bis (fluoroaryl) borane derivative may be reused (recycled)as hydrocarbon solvent.

[0154] By performing the foregoing steps, it is possible to precipitatethe fluoroaryl borane derivative and to isolate the fluoroaryl boranederivative by performing the first filtration. Further, afterconcentrating the filtrate that remains after the first filtration so asto distill off the fluorobenzene, the bis (fluoroaryl) borane derivativeprecipitated as a solid can be separated by the second filtration. Thatis, it is possible to obtain the high-purity fluoroaryl boranederivative and bis (fluoroaryl) borane derivative containing no impuritywith ease and at a low cost.

[0155] As described above, in the method of the present invention forpurifying, since a precipitating condition, a condition for filtrating,and a heating condition with respect to a reaction mixture are employedin a specific order, it is possible to isolate the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative respectively.Further, if a method for producing either the fluoroaryl boranederivative or the bis (fluoroaryl) borane derivative efficiently isemployed, it is possible to produce either the fluoroaryl boranederivative or the bis (fluoroaryl) borane derivative as desired. As aresult, it is possible to obtain the high-purity fluoroaryl borane andbis (fluoroaryl) borane derivative more easily.

[0156] Further, since the method of the present invention for purifyingis completely different from prior arts in the purifying steps, boroxinegenerated in prior arts is not generated. Consequently, it is possibleto obtain the high-purity fluoroaryl borane derivative and bis(fluoroaryl) borane derivative more easily.

BEST MODE FOR CARRYING OUT THE INVENTION

[0157] The present invention is explained in more detail below referringto examples. However, the present invention is not limited to those.Note that NMR (Nuclear Magnetic Resonance) spectrum data was measured inthe examples in such a manner that tetramethylsilane (TMS) was astandard substance for ¹H-NMR spectrum data, while trifluoro acetic acidwas a standard substance for ¹⁹F- NMR spectrum data so that signals ofthe standard substances were assumed to be 0 ppm. Note that, thefollowing EXAMPLEs 1 and 2 are examples in which much bis (fluoroaryl)borane derivative is generated, and EXAMPLE 3 is an example in whichmuch fluoroaryl borane derivative is generated.

[EXAMPLE 1]

[0158] 2064.22 g of IsoparE (supplied from Exxon Corp.) solutioncontaining 56.766 g (0.1109 mol) of tris (pentafluorophenyl) borane astris (fluoroaryl) borane and 2.020 g (0.1121 mol) of water were addedinto a reaction vessel equipped with a reflux condenser, a thermometer,a dropping funnel and a stirrer.

[0159] Next, the content of the reaction vessel was heated to 100° C.with stirring. Reaction was carried out for 4 hours at 100° C. A part ofthe reaction mixture obtained from the reaction for 4 hours was analyzedby ¹⁹F-NMR. It showed that the reaction mixture contained 50.60 mol % ofbis (pentafluorophenyl) borinic acid, 0.87 mol % of pentafluorophenylboronic acid, 48.40 mol % of pentafluorobenzene, and 0.10 mol % of tris(pentafluorophenyl) borane.

[0160] A distillation apparatus was used instead of the reflux condenserprovided on the reactor so as to perform reduced pressure distillationunder a condition of 6.7 kPa (50 mmHg). At this time, an amount ofdistillate was 1731.54 g.

[0161] A residue (concentrated solution) obtained by the reducedpressure distillation was kept at 60° C., and the precipitation, namely,the pentafluorophenyl boronic acid corresponding to the fluoroarylborane derivative was precipitated. Thereafter, the distillate wasfiltrated so as to isolate the pentafluorophenyl boronic acid. Further,the filtrate obtained by filtrating the distillate was cooled down to15° C., and the precipitation, namely, the bis (pentafluorophenyl)borinic acid corresponding to the bis (fluoroaryl) borane derivative wasprecipitated. Thereafter, a cake obtained by filtrating the distillatewas washed with 40 ml of hexane so as to dry the cake at 70° C. under areduced pressure. A weight of the dried cake was 29.987 g. The cake wasanalyzed by ¹⁹F-NMR. It showed that the cake contained 0% of thepentafluorophenyl boronic acid and 100 weight % of bis(pentafluorophenyl) borinic acid.

[0162] As described above, according to the method of the presentinvention for purifying, it is possible to obtain the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative from the solutioncontaining pentafluorophenyl boronic acid which functions as thefluoroaryl borane derivative, bis (pentafluorophenyl) borinic acid whichfunctions as the bis (fluoroaryl) borane derivative, pentafluorobenzenewhich functions as the fluorobenzene, and IsoparE which functions as thehydrocarbon solvent, with ease and at a low cost.

[0163] Note that, NMR spectrum data of the bis (pentafluorophenyl)borinic acid in the cake was as follows: ¹⁹F-NMR (benzene—d6 , δ);−57.6, −72.2, −85.6 ppm

[EXAMPLE 2]

[0164] 809.56 g of IsoparE (supplied from Exxon Corp.) solution ofIsoparE containing 22.263 g (0.0435 mol) of tris (pentafluorophenyl)borane as tris (fluoroaryl) borane and 0.941 g (0.0522 mol) of waterwere added into a reaction vessel equipped with a reflux condenser, athermometer, a dropping funnel and a stirrer.

[0165] Next, the content of the reaction vessel was heated to 100° C.with stirring. Reaction was carried out for 4 hours at 100° C. A part ofthe reaction mixture obtained from the reaction for 4 hours was analyzedby ¹⁹F-NMR. It showed that the reaction mixture contained 49.3 mol % ofbis (pentafluorophenyl) borinic acid, 1.1 mol % of pentafluorophenylboronic acid, 49.4 mol % of pentafluorobenzene, and 0.2 mol % of tris(pentafluorophenyl) borane.

[0166] A distillation apparatus was used instead of the reflux condenserprovided on the reactor so as to perform reduced pressure distillationunder a condition of 8.7 kPa (65 mmHg). At this time, an amount ofdistillate was 703.86 g.

[0167] A residue (concentrated solution) obtained by the vacuumconcentration was kept at 65° C., and the precipitation, namely, thepentafluorophenyl boronic acid corresponding to the fluoroaryl boranederivative was precipitated. Thereafter, the distillate was filtrated soas to isolate the pentafluorophenyl boronic acid. Further, the filtrateobtained by filtrating the distillate was cooled down to 7° C., and theprecipitated material, namely, the bis (pentafluorophenyl) borinic acidcorresponding to the bis (fluoroaryl) borane derivative wasprecipitated. Thereafter, a cake obtained by filtrating the distillatewas washed with 20 ml of hexane so as to dry the cake under a reducedpressure. A weight of the dried cake was 12.540 g. The cake was analyzedby ¹⁹F-NMR. It showed that the cake contained 98.6 weight % of the bis(pentafluorophenyl) borinic acid, 0.6 weight % of the pentafluorophenylboronic acid, and 0.8 weight % of pentafluoro benzene.

[0168] As described above, according to the method of the presentinvention for purifying, it is possible to obtain the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative from the solutioncontaining bis (pentafluorophenyl) borinic acid which functions as thebis (fluoroaryl) borane derivative, pentafluorophenyl boronic acid whichfunctions as the fluoroaryl borane derivative, pentafluorobenzene whichfunctions as the fluorobenzene, and IsoparE which functions as thehydrocarbon solvent, with ease and at a low cost.

[0169] Note that, NMR spectrum data of the pentafluorophenyl boronicacid in the cake was as follows: ¹⁹F-NMR (benzene—d6 , δ); −57.3, −75.1,−86.4 ppm

[EXAMPLE 3]

[0170] 1139.76 g of an ethylcyclohexane solution containing 41.695 g(0.0814 mol) of tris (pentafluorophenyl) borane as tris (fluoroaryl)borane and 4.404 g (0.2444 mol) of water were added into a reactionvessel equipped with a reflux condenser, a thermometer, a droppingfunnel and a stirrer.

[0171] Next, the content of the reaction vessel was heated to 100° C.with stirring. Reaction was carried out for 18 hours at A distillationapparatus was used instead of the reflux cooler provided on the reactorso as to perform vacuum concentration under a condition of 6.7 kPa (50mmHg). At this time, an amount of distillate was 653.66 g.

[0172] A residue (concentrated solution) obtained by the vacuumconcentration was kept at 60° C., and the precipitated material, namely,the pentafluorophenyl boronic acid corresponding to the fluoroarylborane derivative was precipitated. Thereafter, the distillate wasfiltrated so as to isolate the pentafluorophenyl boronic acid. A cakeobtained by filtrating the distillate was washed with 100 ml of hexaneso as to dry the cake at 40° C. under a reduced pressure. A weight ofthe dried cake was 8.5582 g. The cake was analyzed by ¹⁹F-NMR. It showedthat the cake contained 100 weight % of the pentafluorophenyl boronicacid.

[0173] As described above, according to the method of the presentinvention for purifying, it is possible to obtain the fluoroaryl boranederivative from the solution containing pentafluorophenyl boronic acidwhich functions as the fluoroaryl borane derivative, bis(pentafluorophenyl) borinic acid which functions as the bis (fluoroaryl)borane derivative, pentafluorobenzene which functions as the benzenefluoride, and ethylcyclohexane which functions as the hydrocarbonsolvent, with ease and at a low cost.

[0174] Note that, NMR spectrum data of the pentafluorophenyl boronicacid in the cake was as follows: ¹⁹F-NMR (acetone—d6, δ); −57.7, −79.9,−86.6 ppm Further, MS (mass spectrum) data of the pentafluorophenylboronic acid in the cake was as follows: MASS (M/Z); 212

[0175] The invention being thus described, it will be obvious that thesame may be varied in many ways. Such variations are not to be regardedas a departure from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art intended tobe included within the scope of the following claims.

INDUSTRIAL APPLICABILITY

[0176] A method of the present invention for purifying a fluoroarylborane derivative and a bis (fluoroaryl) borane derivative, as describedabove, includes the steps of: precipitating the fluoroaryl boranederivative from a solution containing the fluoroaryl borane derivative,the bis (fluoroaryl) borane derivative, and a hydrocarbon solvent;performing first filtration so that the fluoroaryl borane derivative isisolated; cooling a filtrate that has been obtained by the firstfiltration; precipitating the bis (fluoroaryl) borane derivative; andperforming second filtration.

[0177] A method of the present invention for purifying a fluoroarylborane derivative and a bis (fluoroaryl) borane derivative, as describedabove, includes the steps of: precipitating the fluoroaryl boranederivative from a solution containing the fluoroaryl borane derivative,the bis (fluoroaryl) borane derivative, fluorobenzene, and a hydrocarbonsolvent; performing first filtration so that the fluoroaryl boranederivative is isolated as a solid; precipitating the bis (fluoroaryl)borane derivative from a filtrate that has been obtained by the firstfiltration; and performing second filtration.

[0178] A method of the present invention for purifying a fluoroarylborane derivative and a bis (fluoroaryl) borane derivative, as describedabove, includes the steps of: concentrating a solution containing thebis (fluoroaryl) borane derivative, the fluorobenzene, and a hydrocarbonsolvent so as to remove fluorobenzene from the solution; precipitatingthe fluoroaryl borane derivative; performing first filtrate so that thefluoroaryl borane derivative is isolated; cooling a filtrate that hasbeen obtained by the first filtration; precipitating the bis(fluoroaryl) borane derivative; and performing second filtration.

[0179] A method of the present invention for purifying a fluoroarylborane derivative and a bis (fluoroaryl) borane derivative, as describedabove, includes the steps of: precipitating the fluoroaryl boranederivative from a solution containing the fluoroaryl borane derivative,the bis (fluoroaryl) borane derivative, fluorobenzene, and a hydrocarbonsolvent; performing first filtration so that the fluoroaryl boranederivative is isolated; concentrating a filtrate that has been obtainedby the first filtration so as to remove the fluorobenzene from thefiltrate; precipitating the bis (fluoroaryl) borane derivative from thefiltrate; and performing second filtration.

[0180] A method of the present invention for purifying a fluoroarylborane derivative and a bis (fluoroaryl) borane derivative, as describedabove, is arranged so that: a solution containing the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative is obtained byreacting tris (fluoroaryl) borane with a compound (5) in a molar ratiofrom 1:1.9 to 1:5 in a hydrocarbon solvent.

[0181] A method of the present invention for purifying a fluoroarylborane derivative and a bis (fluoroaryl) borane derivative, as describedabove, is arranged so that: a solution containing the fluoroaryl boranederivative and the bis (fluoroaryl) borane derivative is obtained byreacting tris (fluoroaryl) borane with a compound (5) in a molar ratiofrom 1:0.9 to 1:1.1 in a hydrocarbon solvent.

[0182] A method of the present invention for purifying a fluoroarylborane derivative and a bis (fluoroaryl) borane derivative, as describedabove, is arranged so that: the hydrocarbon solvent is substantially analiphatic hydrocarbon solvent.

[0183] Therefore, since the fluorobenzene can be removed by performingsimple operations (steps), it is possible to purify the fluoroarylborane derivative and the bis (fluoroaryl) borane derivative with easeand at a low cost. That is, it is possible to obtain the highly-purifiedfluoroaryl borane derivative and bis (fluoroaryl) borane derivativecontaining no impurity with ease and at a low cost.

[0184] A fluoroaryl borane derivative of the present invention, asdescribed above, is arranged to contain a bis (fluoroaryl) boranederivative so that the content of the bis (fluoroaryl) borane derivativeis not more than 1 weight %.

[0185] A fluoroaryl borane derivative of the present invention isarranged to have purity of not less than 90%.

[0186] A bis (fluoroaryl) borane derivative of the present invention, asdescribed above, is arranged to contain a fluoroaryl borane derivativeso that the content of the fluoroaryl borane derivative is not more than1%.

[0187] A bis (fluoroaryl) borane derivative of the present invention isarranged to have purity of not less than 95%.

[0188] A method of the present invention for purifying a fluoroarylborane derivative, as described above, is arranged to react tris(fluoroaryl) borane with a compound (5) in a molar ratio from 1:1.9 to1:1.5 in a hydrocarbon solvent.

[0189] A fluoroaryl borane derivative obtained by a method of thepresent invention for producing a fluoroaryl borane derivative, asdescribed above, is arranged to have purity of not less than 90%.

[0190] Therefore, it is possible to industrially use a fluoroaryl boranederivative and a bis (fluoroaryl) borane derivative as catalysts and thelike.

What is claimed is:
 1. A method for purifying a fluoroaryl boranederivative and a bis (fluoroaryl) borane derivative comprising the stepsof: precipitating the fluoroaryl borane derivative from a solutioncontaining the fluoroaryl borane derivative, the bis (fluoroaryl) boranederivative, and a hydrocarbon solvent; performing first filtration sothat the fluoroaryl borane derivative is isolated; precipitating the bis(fluoroaryl) borane derivative from a filtrate, that has been obtainedby the first filtration, after performing the first filtration; andperforming second filtration so that the bis (fluoroaryl) boronderivative is isolated, said fluoroaryl borane derivative beingrepresented by General Formula (1):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents a hydrogenatom or a hydrocarbon group, and M represents an atom belonging to Group5B or Group 6B, and n represents 0 or 1), said bis (fluoroaryl) boranederivative being represented by General Formula (2):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ representing thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1).
 2. A methodfor purifying a fluoroaryl borane derivative and a bis (fluoroaryl)borane derivative comprising the steps of: precipitating the fluoroarylborane derivative from a solution containing the fluoroaryl boranederivative, the bis (fluoroaryl) borane derivative, fluorobenzene, and ahydrocarbon solvent; performing first filtration so that the fluoroarylborane derivative is isolated as a solid; precipitating the bis(fluoroaryl) borane derivative from a filtrate, that has been obtainedby the first filtration, after performing the first filtration; andperforming second filtration so that the bis (fluoroaryl) boranederivative is isolated as a solid, said fluoroaryl borane derivativebeing represented by General Formula (1):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), said bis(fluoroaryl) borane derivative being represented by General Formula (2):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ representing thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), saidfluorobenzene being represented by General Formula (3):

(where each of R⁹, R¹⁰, R¹¹, R¹², and R¹³ independently represents oneof a hydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R⁹, R¹⁰, R¹¹, R¹², and R¹³ represents thefluorine atom, R⁸ represents one of a hydrogen atom and a hydrocarbongroup).
 3. A method for purifying a fluoroaryl borane derivative and abis (fluoroaryl) borane derivative comprising the steps of:precipitating the fluoroaryl borane derivative from a solution,containing the fluoroaryl borane derivative, the bis (fluoroaryl) boranederivative, and a hydrocarbon solvent, that has been obtained byremoving fluorobenzene from a solution containing the fluoroaryl boranederivative, the bis (fluoroaryl) borane derivative, the fluorobenzene,and the hydrocarbon solvent; performing first filtration so that thefluoroaryl borane derivative is isolated as a solid; precipitating thebis (fluoroaryl) borane derivative from a filtrate, that has beenobtained by the first filtration, after performing the first filtration;and performing second filtration so that the bis (fluoroaryl) boranederivative is isolated as a solid, said fluoroaryl borane derivativebeing represented by General Formula (1):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), said bis(fluoroaryl) borane derivative being represented by General Formula (2):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), saidfluorobenzene being represented by General Formula (3):

(where each of R⁹, R¹⁰, R¹¹, R¹², and R¹³ independently represents oneof a hydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R⁹, R¹⁰, R¹¹, R¹², and R¹³ represents thefluorine atom, R⁸ represents one of a hydrogen atom and a hydrocarbongroup).
 4. A method for purifying a fluoroaryl borane derivative and abis (fluoroaryl) borane derivative comprising the steps of:precipitating the fluoroaryl borane derivative from a solutioncontaining the fluoroaryl borane derivative, the bis (fluoroaryl) boranederivative, fluorobenzene, and a hydrocarbon solvent; performing firstfiltration so that the fluoroaryl borane derivative is isolated as asolid; precipitating the bis (fluoroaryl) borane derivative from ahydrocarbon solution, that has been obtained by removing thefluorobenzene, after performing the first filtration; and performingsecond filtration so that the bis (fluoroaryl) borane derivative isisolated as a solid, said fluoroaryl borane derivative being representedby General Formula (1):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), said bis(fluoroaryl) borane derivative being represented by General Formula (2):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), saidfluorobenzene being represented by General Formula (3):

(where each of R⁹, R¹⁰, R¹¹, R¹², and R¹³ independently represents oneof a hydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, at least one of R⁹, R¹⁰, R¹¹, R¹², and R¹³ representing thefluorine atom, R⁸ represents one of a hydrogen atom and a hydrocarbongroup).
 5. The method as set forth in any one of claims 1 to 4, whereinthe solution containing the fluoroaryl borane derivative and the bis(fluoroaryl) borane derivative is obtained by reacting tris (fluoroaryl)borane with a compound represented by General Formula (5) in a molarratio from 1:1.9 to 1:5 in the hydrocarbon solvent, said tris(fluoroaryl) borane being represented by General Formula (4):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, at least one of R¹, R², R³, R⁴, and R⁵ representing the fluorineatom), said compound being represented by General Formula (5):R⁶—MR¹⁴(R⁷)n  (5) (where each of R⁶, R⁷, and R¹⁴ independentlyrepresents one of a hydrogen atom and a hydrocarbon group, and Mrepresents an atom belonging to Group 5a or Group 6a, and n represents 0or 1).
 6. The method as set forth in any one of claims 1 to 4, whereinthe solution containing the fluoroaryl borane derivative and the bis(fluoroaryl) borane derivative is obtained by reacting tris (fluoroaryl)borane with a compound represented by General Formula (5) in a molarratio from 1:0.9 to 1:1.1 in the hydrocarbon solvent, said tris(fluoroaryl) borane being represented by General Formula (4):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom), said compound is represented by General Formula (5):R⁶—MR¹⁴(R⁷)n  (5) (where each of R⁶, R⁷, and R¹⁴ independentlyrepresents one of a hydrogen atom and a hydrocarbon group, and Mrepresents an atom belonging to Group 5a or Group 6a, and n represents 0or 1).
 7. The method as set forth in any one of claims 1 to 6, whereinthe hydrocarbon solvent is substantially an aliphatic hydrocarbonsolvent.
 8. A fluoroaryl borane derivative comprising a solidrepresented by General Formula (1):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, at least one of R¹, R², R³, R⁴, and R⁵ representing the fluorineatom, and each of R⁶ and R⁷ independently represents one of a hydrogenatom and a hydrocarbon group, and M represents an atom belonging toGroup 5b or Group 6B, and n represents 0 or 1), wherein the fluoroarylborane derivative contains a bis (fluoroaryl) borane derivative so thata content of the bis (fluoroaryl) borane derivative is not more than 1%by weight, said bis (fluoroaryl) borane derivative being represented byGeneral Formula (2):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1).
 9. Thefluoroaryl borane derivative as set forth in claim 8, wherein thefluoroaryl borane derivative has purity of not less than 90%.
 10. A bis(fluoroaryl) borane derivative comprising a solid represented by GeneralFormula (2):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1), wherein thebis (fluoroaryl) borane derivative contains a fluoroaryl boranederivative so that a content of the fluoroaryl borane derivative is notmore than 1% by weight, said fluoroaryl borane derivative beingrepresented by General Formula (1):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom, and each of R⁶ and R⁷ independently represents one of ahydrogen atom and a hydrocarbon group, and M represents an atombelonging to Group 5B or Group 6B, and n represents 0 or 1).
 11. The bis(fluoroaryl) borane derivative as set forth in claim 10, wherein the bis(fluoroaryl) borane derivative has purity of not less than 95%.
 12. Amethod for producing a fluoroaryl borane derivative comprising the stepof reacting tris (fluoroaryl) borane with a compound represented byGeneral Formula (5) in a molar ratio from 1:1.9 to 1:5 in a hydrocarbonsolvent, said tris (fluoroaryl) borane being represented by GeneralFormula (4):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, and at least one of R¹, R², R³, R⁴, and R⁵ represents thefluorine atom), said compound being represented by General Formula (5):R⁶—MR¹⁴(R⁷)n  (5) (where each of R⁶, R⁷, and R¹⁴ independentlyrepresents one of a hydrogen atom and a hydrocarbon group, and Mrepresents an atom belonging to Group 5a or Group 6a, and n represents 0or 1), said fluoroaryl borane derivative being represented by GeneralFormula (1):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, at least one of R¹, R², R³, R⁴, and R⁵ representing the fluorineatom, and each of R⁶ and R⁷ independently represents one of a hydrogenatom and a hydrocarbon group, and M represents an atom belonging toGroup 5B or Group 6B, and n represents 0 or 1).
 13. The method as setforth in claim 12, wherein the fluoroaryl borane derivative contains thebis (fluoroaryl) borane derivative so that a content of the bis(fluoroaryl) borane derivative is not more than 1% by weight, said bis(fluoroaryl) borane derivative being represented by General Formula (2):

(where each of R¹, R², R³, R⁴, and R⁵ independently represents one of ahydrogen atom, a fluorine atom, a hydrocarbon group, and an alkoxygroup, at least one of R¹, R², R³, R⁴, and R⁵ representing the fluorineatom, and each of R⁶ and R⁷ independently represents one of a hydrogenatom and a hydrocarbon group, and M represents an atom belonging toGroup 5B or Group 6B, and n represents 0 or 1).
 14. The method as setforth in claim 12 or 13, wherein the fluoroaryl borane derivative haspurity of not less than 90%.